HEAT SUPPLY. 53 



of endurance, totally eclipsing the performances done in 

 former days, is mainly owing to a larger supply of fat 

 and starch having been introduced into the diet of 

 athletes. This lesson we should utilize in the case of 

 hard-worked horses. Unfortunately our choice in the 

 matter of food is here but small, when we are limited 

 in the matter of expense, except in the case of linseed, 

 which is a thoroughly suitable article. We might, 

 however, in some cases, supplement it with milk, eggs, 

 ghee (clarified butter), and goor (unrefined sugar). 



We find that, for the maintenance of health, a man 

 requires, in his food, a supply of fat as well as of starch, 

 and that the former cannot be replaced altogether by 

 the latter. The horse, it appears, is far more indepen- 

 dent of a supply of fat in his diet, than is man ; but 

 whether it can be dispensed with altogether or not, is a 

 question I am unable to answer. The fact, however, 

 of the existence of a certain, though varying proportion 

 of fat, in the natural food of the animal, indicates its 

 value, if not its absolute necessity. In the daily diet, 

 given by Dr. Parkes, for a man performing very laborious 

 work, we find that the fat is to the starch and sugar, as 

 one is to four. The proportion for a horse, on a full 

 supply of oats and hay, is about one to sixty. 



In food for horses, it appears that sugar may be 

 entirely replaced by starch, though the converse of this 

 does not hold good. 



Heat Supply. The constant oxidation of carbon 

 and hydrogen attended by the formation of carbonic 

 acid and water in the various tissues, is accompanied 

 by the evolution of heat, which serves to sustain the 

 internal temperature of the body of the horse at about 



